1. Technical Field
The present invention relates to image forming apparatuses, image forming methods and image forming systems.
2. Related Art
Image forming apparatuses such as laser beam printers are already well known. Such image forming apparatuses include, for example, an image bearing member for bearing latent images, and a developer bearing member that rotates while bearing developer to transport the developer to a position opposing the image bearing member. When image signals or the like are transmitted from an external apparatus such as a host computer, latent images borne on the image bearing member are developed using the developer that has been transported to the opposing position by the developer bearing member, thereby forming developer images. Then, the developer images are transferred onto a medium so as to ultimately form images on the medium.
During development of the latent images using developer, some of such image forming apparatuses apply to the developer bearing member an alternating voltage that includes a first voltage for shifting developer from the developer bearing member to the image bearing member, and a second voltage for shifting developer from the image bearing member to the developer bearing member.
Regularly disposed concave sections are sometimes provided on the surface of the above-described developer bearing member such that a sufficient amount of developer is borne on the surface of the developer bearing member (in other words, in order to ensure a sufficiently large surface area for the surface on which developer is borne), or for other reasons.
However, developer tends to be stuck in the concave section, where the rollability of developer tends to become unfavorable. In addition, in image forming apparatuses that includes a charging member for charging developer borne on the developer bearing member by contacting the developer bearing member, the force of the charging member pressing against developer is weaker at the concave sections (compared with convex sections), which may invite inappropriate frictional charging.
For this reason, a developer at the concave sections tends to suffer insufficient charging. As a result, such a developer causes so-called fog.
It should be noted that JP-A-5-142950 and JP-A-2004-219640 are examples of related technology.